Julius Robert von Mayer

Mayer, Julius Robert von, 1814–78, German physician and physicist, studied medicine at Tübingen, Munich, and Paris. From a consideration of the generation of animal heat, he was led to determine the general relationship between heat and work. This resulted in his announcement in 1842, independently of J. P. Joule, of the mechanical equivalence of heat, a consequence of the law of conservation of energy. In 1845 he gave a still more general statement of this law. Controversy arose, however, as to the priority of the discovery, and it was only years later that he received due credit for his contribution.